Looking at the Sea    

The Water PlanetOceans in MotionLife in the SeaScientist at SeaResources


View of the Earth from space
The Earth from space.

If you look down at our planet from outer space, most of what you see is water; 71% of the planet's surface is covered by ocean and it is because of this that the Earth is sometimes called "the water planet". Only about three-tenths of our globe is covered with land.

The ocean wraps the globe and is divided into four major regions: the Atlantic Ocean, the Pacific Ocean, the Indian Ocean and the Arctic Ocean. Some scientists consider the waters around Antarctica to be a separate, fifth ocean as well. These oceans, although distinct in some ways, are all interconnected; the same water is circulated throughout them all.
Diagram showing the continents on one side of the globe and the world ocean covering the rest.
Seventy-one percent of the Earth's surface is ocean.
If all the continents were crammed into one corner of the Earth, the vast extent of the world ocean could easily be seen. In reality, of course, the continents are not bunched together as shown in the figure to the right, but instead are spread out over the entire Earth's surface. Most oceanographers, however, believe that a long time ago in the Earth's geologic history all of the continents were once grouped closely together in much the same manner.

Begin your exploration here looking at the sea:

Physical Features of the Ocean

Facts about the oceans and diagrams showing the main features found on the ocean floor.

The Changing Oceans

Oceans have been created and then destroyed. Find out how the continents have moved throughout geologic history.

The Water Cycle

The oceans are always losing and gaining water in a never ending process called the hydrologic cycle.

Ocean Profiles

Vignettes of the four oceans and some of their varied environments.

Science Learning Network | email: sln@mos.org | © 1998 The Museum of Science